Boris Johnson, the Mayor of London, accused ministers of acting like
‘adolescents’ after being told to get off ‘his backside’ and negotiate with
trade union leaders ahead of proposed Tube strikes.

In the latest sally in the war of words between Downing Street and City Hall, where the mayor is based, Mr Johnson was ordered to “reach out” to the RMT union which is threatening to bring the capital to a standstill over two weeks of strikes.

Swipes from two Liberal Democrat ministers will have infuriated Mr Johnson, who has already accused Downing Street of being “lily-livered” for failing to take legislative action to head of strikes which are expected in a range of sectors this summer.

A source close to Vince Cable, the Business Secretary, suggested that the Mayor should engage in negotiations with Bob Crow, the bullish leader of the RMT.

“Boris should take a lead from the Coalition and reach out to the unions in the first instance before trying to get a change in the law,” the source said.

Ed Davey, the Employment Minister, went further, criticising Mr Johnson for suggesting that the Government should introduce legislation to curb the power of the unions.

Saying that the Mayor had not met RMT leaders for two years, Mr Davey added: “That suggests Boris Johnson should have engaged with Bob Crow and RMT members however difficult they are.

“Boris is trying to pass the buck when actually the buck stops with City Hall.”

In a sign of the increasingly fractious relationship between City Hall and No 10, the Mayor's team is said to believe that the Lib Dem attacks would not have been made unless they had been sanctioned from the top of Government.

A spokesman for the Conservative Mayor said the ministers had overlooked the fact that Mr Johnson had agreed to take part in talks only if the threat of strikes was removed.

He added: “Their criticism betrays a fundamental ignorance and misunderstanding of the coherent and persistent strategy that has been perused at City Hall.”

Mr Johnson wants the Government to introduce a threshold for strike ballots so that industrial action would only be possible if a majority of the workforce voted in favour.

At present, strikes may take place if a small minority support them, if the majority choose not to participate in the ballot.

The RMT strikes, called in support of two sacked Tube drivers, were backed by 29 per cent of the union membership.

Due to take place between next Monday and Friday May 20, with a second wave scheduled for between Monday June 13 and Friday June 17, they will severely inconvenience millions of commuters.

Mr Crow called on the Mayor to intervene to stop the strikes by taking part in negotiations.

He said: "The time has come for common-sense to prevail and for Mayor Boris Johnson and his officials to meet with us directly to resolve this dispute.

"All that we are seeking to do is get our unfairly-dismissed members back to work doing the job that they are being paid by Londoners to do – driving Tube trains."

Mike Brown managing director of London Underground, said: "As we have always said, disputes involving individuals should be dealt with through the mechanisms established for that purpose.

“While that process takes its course, there remains no reason whatsoever for the RMT leadership to seek to disrupt Londoners by threatening strike action."